Flexibility of Commercial Building HVAC Fan as Ancillary Service for Smart Grid

TL;DR

This paper demonstrates that commercial building HVAC fans can provide significant ancillary power flexibility to the smart grid by modulating supply duct pressure, with minimal impact on indoor climate, potentially offering up to 5.6 GW of regulation reserve by 2035.

Contribution

It introduces a novel method of modulating supply duct static pressure to harness HVAC fans for grid ancillary services, validated through empirical data and simulations.

Findings

At least 4 GW of regulation reserve can be provided by commercial buildings in the US.

Intermittent fan operation does not affect indoor climate noticeably.

Proposed control scheme improves grid frequency regulation using building thermal slack.

Abstract

In this paper, we model energy use in commercial buildings using empirical data captured through sMAP, a campus building data portal at UC Berkeley. We conduct at-scale experiments in a newly constructed building on campus. By modulating the supply duct static pressure (SDSP) for the main supply air duct, we induce a response on the main supply fan and determine how much ancillary power flexibility can be provided by a typical commercial building. We show that the consequent intermittent fluctuations in the air mass flow into the building does not influence the building climate in a human-noticeable way. We estimate that at least 4 GW of regulation reserve is readily available only through commercial buildings in the US. Based on predictions this value will reach to 5.6 GW in 2035. We also show how thermal slack can be leveraged to provide an ancillary service to deal with transient frequency fluctuations in the grid. We consider a simplified model of the grid power system with time varying demand and generation and present a simple control scheme to direct the ancillary service power flow from buildings to improve on the classical automatic generation control (AGC)-based approach. Simulation results are provided to show the effectiveness of the proposed methodology for enhancing grid frequency regulation.